 
 (defn vary-pitch [{:keys [::pitch ::variation ::direction]}]
   (let [direction (or direction [-1 1])
-        a (descriptor->value pitch)
-        b (+ a (* (descriptor->value variation)
-                  (descriptor->value direction)))]
+        a         (descriptor->value pitch)
+        b         (+ a (* (descriptor->value variation)
+                          (descriptor->value direction)))]
     [a b]))
 
 (s/fdef vary-pitch

        (uc/initial-state Exercise nil)
        {::name       "rhythm-reading"
         ::options    [["0" "A"] ["1" "B"] ["2" "C"] ["3" "D"]]
         ::play-notes (let [last-play (atom [])
                            time-multiplier 0.7]
                        (fn [notes]
                          (let [time (audio/current-time)
                                nodes (map #(update % ::audio/duration (partial * time-multiplier)) (prepare-notes notes))
                                metro (map #(update % ::audio/duration (partial * time-multiplier)) (prepare-notes rhytm-metronome))]
                            (run! audio/stop @last-play)

  static IExercise
  (new-round [_ props]
    (let [{::keys [read-note-order read-note]} props
          pos    (rand-int-new (count read-note-order) read-note)
          note   (get read-note-order pos)
          octave (if (> pos 4) 4 3)
          notes  [(str note octave)]]
      (assoc props
        ::read-note pos
        ::notes notes
